This application claims the benefit of Japanese Application No. 2001-300376 filed Sep. 28, 2001.
The present invention relates to a support apparatus, magnet system and magnetic resonance imaging apparatus, and particularly to a support apparatus capable of placing a support plate, which horizontally supports a supported object, either over a base or off the base, a magnet system for a magnetic resonance imaging apparatus comprising such a support apparatus, and a magnetic resonance imaging apparatus comprising such a magnet system.
In a magnetic resonance imaging (MRI) apparatus, a subject to be imaged is carried into an internal space of a magnet syster i.e., an imaging space; a static magnetic field, gradient magnetic fields and a high frequency magnetic field are applied to excite spins within the subject to generate magnetic resonance signals; and an image is reconstructed based on the received signals.
One type of the magnet system is the open magnet system. The open magnet system has a structure in which a pair of magnets vertically facing each other across the imaging space are supported by a C-shaped yoke. The magnet system having such a structure provides high openness because the vertical yoke is disposed only on one side.
The subject to be imaged is carried into the imaging space of such a magnet system, being rested on a movable bed having wheels. The carrying is achieved by horizontal movement of the movable bed from the front of the magnet system. Such a carrying scheme facilitates access to the subject during imaging, and allows efficient use of the internal space of the magnet system.
In the MRI apparatus employing the movable bed to carry the subject into the imaging space as described above, the bed for supporting the subject and the magnet system for receiving the bed are separate. Therefore, the positional relationship between the bed and the magnet system while receiving the bed is not fixed.
It is therefore an object of the present invention to provide a support apparatus in which the positional relationship between a support section for supporting a supported object and a base section for receiving the support section is always fixed, a magnet system comprising such a support apparatus, and a magnetic resonance imaging apparatus comprising such a magnet system.
(1) The present invention, in accordance with one aspect thereof for solving the aforesaid problem, is a support apparatus characterized in comprising: a support section for horizontally supporting a supported object; a base section having a horizontal plane on its top; and a position adjusting section provided between said support section and said base section, for moving said support section forward/backward between a position above said horizontal plane and a position off said horizontal plane while keeping said support section at a level higher than said horizontal plane, and for moving said support section upward/downward between a position higher than said horizontal plane and a position lower than said horizontal plane at said position off said horizontal plane.
(2) The present invention, in accordance with another aspect thereof for solving the aforesaid problem, is a magnet system for a magnetic resonance imaging apparatus that has a space for receiving a subject to be imaged and generates a static magnetic field, gradient magnetic field and high frequency magnetic field in said space, characterized in comprising: a base section having a horizontal plane on its top; a post section provided on one side of said base section and extending upright beyond said horizontal plane; a hood section supported by said post section, facing said horizontal plane across said space; a support section for horizontally supporting the subject to be imaged; and a position adjusting section provided between said base section and said support section, for moving said support section forward/backward between a position above said horizontal plane and a position off said horizontal plane on the other side of said base section while keeping said support section at a level higher than said horizontal plane, and for moving said support section upward/downward between a position higher than said horizontal plane and a position lower than said horizontal plane at said position off said horizontal plane.
(3) The present invention, in accordance with still another aspect thereof for solving the aforesaid problem, is a magnetic resonance imaging apparatus having: a magnet system that has a space for receiving a subject to be imaged and generates a static magnetic field, gradient magnetic field and high frequency magnetic field in said space; and image producing means for producing an image based on magnetic resonance signals acquired through said magnet system, characterized in that said magnet system comprises: a base section having a horizontal plane on its top; a post section provided on one side of said base section and extending upright beyond said horizontal plane; a hood section supported by said post section, facing said horizontal plane across said space; a support section for horizontally supporting the subject to be imaged; and a position adjusting section provided between said base section and said support section, for moving said support section forward/backward between a position above said horizontal plane and a position off said horizontal plane on the other side of said base section while keeping said support section at a level higher than said horizontal plane, and for moving said support section upward/downward between a position higher than said horizontal plane and a position lower than said horizontal plane at said position off said horizontal plane.
In the present invention of the aspects as described regarding (1)-(3), a position adjusting section for moving the support section forward/backward between a position above a horizontal plane at the top of the base section and a position off the horizontal plane while keeping the support section at a level higher than the horizontal plane, and for moving the support section upward/downward between a position higher than the horizontal plane and a position lower than the horizontal plane at the position off the horizontal plane, is provided between the base section and the support section; and therefore, the positional relationship between the support section and the base section for receiving it can be always fixed.
Preferably, said position adjusting section comprises a pair of link mechanisms respectively provided between two positions of said support section along a direction parallel with said horizontal plane and perpendicular to the direction of said forward/backward movement and the corresponding end portions of said base section, said link mechanisms being pivotally rotatable relative to said base section; and a movement mechanism for moving a portion of said pair of link mechanisms adjacent to said base section in the direction of said forward/backward movement, so that the position adjustment of the support section can be suitably achieved.
Preferably, each member of said pair of link mechanisms comprises a pair of arms configured to avoid mutual interference involved in said pivotal rotation so that the upward/downward movement can be suitably achieved.
(4) The present invention, in accordance with still another aspect thereof for solving the aforesaid problem, is a support apparatus characterized in comprising: a support section for horizontally supporting a supported object; a base section having a horizontal plane on its top; and a position adjusting section provided between said support section and said base section, for moving said support section forward/backward between a position above said horizontal plane and a position off said horizontal plane while keeping said support section at a level higher than said horizontal plane.
(5) The present invention, in accordance with still another aspect thereof for solving the aforesaid problem, is a magnet system for a magnetic resonance imaging apparatus that has a space for receiving a subject to be imaged and generates a static magnetic field, gradient magnetic field and high frequency magnetic field in said space, characterized in comprising: a base section having a horizontal plane on its top; a post section provided on one side of said base section and extending upright beyond said horizontal plane; a hood section supported by said post section, facing said horizontal plane across said space; a support section for horizontally supporting the subject to be imaged; and a position adjusting section provided between said base section and said support section, for moving said support section forward/backward between a position above said horizontal plane and a position off said horizontal plane on the other side of said base section while keeping said support section at a level higher than said horizontal plane.
(6) The present invention, in accordance with still another aspect thereof for solving the aforesaid problem, is a magnetic resonance imaging apparatus having: a magnet system that has a space for receiving a subject to be imaged and generates a static magnetic field, gradient magnetic field and high frequency magnetic field in said space; and image producing means for producing an image based on magnetic resonance signals acquired through said magnet system, characterized in that said magnet system comprises: a base section having a horizontal plane on its top; a post section provided on one side of said base section and extending upright beyond said horizontal plane; a hood section supported by said post section, facing said horizontal plane across said space; a support section for horizontally supporting the subject to be imaged; and a position adjusting section provided between said base section and said support section, for moving said support section forward/backward between a position above said horizontal plane and a position off said horizontal plane on the other side of said base section while keeping said support section at a level higher than said horizontal plane.
In the present invention of the aspects as described regarding (4)-(6), a position adjusting section for moving the support section forward/backward between a position above a horizontal plane at the top of the base section and a position off the horizontal plane while keeping the support section at a level higher than the horizontal plane, is provided between the support section and the base section; and therefore, the positional relationship between the support section and the base section for receiving it can be always fixed.
Preferably, said position adjusting section comprises a pair of extendable arms respectively provided between two positions of said support section along a direction parallel with said horizontal plane and perpendicular to the direction of said forward/backward movement and the corresponding end portions of said base section, said extendable arms being capable of extending relative to said base section, so that the forward/backward movement of the support section can be suitably achieved.
Preferably, said position adjusting section comprises a pair of arms respectively provided between two positions of said support section along a direction parallel with said horizontal plane and perpendicular to the direction of said forward/backward movement and the corresponding end portions of said base section; and a movement mechanism for enabling a portion of said support arms adjacent to said base section to move in the direction of said forward/backward movement, so that the forward/backward movement of the support section can be suitably achieved.
Therefore, the present invention can provide a support apparatus in which the positional relationship between a support section for supporting a supported object and a base section for receiving the support section is always fixed, a magnet system comprising such a support apparatus, and a magnetic resonance imaging apparatus comprising such a magnet system.
Further objects and advantages of the present invention will be apparent from the following description of the preferred embodiments of the invention as illustrated in the accompanying drawings.